Kohata Anime Studio is a place full of dreams where animation is made. Baja was raised in this studio by the people who create animation. Floating in a pond outside are his friends the ducks. One night, when all the people are no longer at the studio, Baja takes a peek outside and finds that his duck friends are being attacked by a cat. Will Baja be able to save his friends? A wondrous night adventure begins.

Four boys named Haruka, Makoto, Nagisa and Rin all participated in a swimming tournament shortly before graduating elementary school and later parted ways. Years later, they reunite when Rin challenges Haruka to a race and wins. Not wanting to be defeated so easily, Haruka gathers Makoto and Nagisa and a new recruit named Rei to form the Iwatobi High School Swimming Club.